The high-amplitude \(\delta \)  Sct stars tend to rotate slower (typically \(v\sin i \le 30\)  km/s) than
normal \(\delta \)  Sct stars, which tend
to have \(v\sin i \ge 150\)  km/s [1]}, [2]}.
This suggests that different angular momentum transport mechanisms
are at work in these two groups of \(\delta \,\) Sct stars, or
different efficiencies of the same mechanism. The origin of this transport is poorly understood
[3]}.
To investigate the relation between the oscillation amplitude and the stellar rotation, we cross-matched
the stars classified as \(\delta \)  Sct stars in our sample described in section 
with those in the Gaia-DR3 archive for which a \(v\sin i\)  value is available from Gaia spectroscopy
(vsini_esphs) with a formal precision better than 50%. This returned 3515 sources, which we
partitioned into ten bins in \(v\sin i\) , each with a width of 15 km s\(^{-1}\) . For each bin, we computed the
median value of the photometric amplitude \(A_{G,1}\) . As expected, the bins are not equally populated.
All bins contain at least 220 stars, except for the
bin with the most rapid rotators for which
the constraint on the \(v\sin i\)  precision resulted in only 29 stars. The result is shown in
Fig. REF .
The dark blue line denotes the median amplitude for each bin, and
the light blue band shows the 25%-75% quantile interval of photometric amplitude \(A_{G,1}\)  in
each bin. A clear and steady decline in median amplitude can be seen with increasing \(v\sin i\) 
at a rate of roughly 46 \(\mu \) mag per km s\(^{-1}\) .
<FIGURE>